Method of producing homogeneous liquids



Sept. 5, 1933.

W. H. BROOKS METHOD OF PRODUCING HOMOGENEOUS LIQUIDS Original Filed July7, 1928 A 77URNE).

Patented Sept. 5, .1933 Y a i Q s I lVlE'llHGD F PRODUCING HOMOGENEOUSLIQUIDS William H. Brooks, OconomoWoc, Wis.,assignor to @arnationCompany, Milwaukee, Wis, a corporation of Delaware @riginal applicationJuly 7, 1928, Serial No. 291,018. Divided and thisv applicationSepteinber 14, 1929. Serial No. 392,607. g h

1 Glairn. (CI. 99-41) This invention relates to an improved method ormaterially retard separation of butter fat in for producing homogeneousliquids, especially the containers during the interval between theliquids which are a mixture of two or more inmanufacture of the milk andconsumption, as gredients differing in density and other characwell asto make a more palatable, uniform,

5 teristics; 1 smooth and lumpless product; for icecream the 60 Anobject of the invention is to provide a methsame procedure may befollowed. 0d of homogenization by which the defects of Further myinvention is by no means restricted previous improvements in this fieldare obviated. to the treatment of milk and milk products, butHere-tofore liquids to be rendered homogeneous it can be utilized forthe compounding of lubriand uniform in composition; especially liquidscating oils with grades of oil of various density 5 containing one ormore fatty or oilysubstances, and viscosity, to secure uniformity,throughout such as milk bearing globules of butter fat; have and avoidseparation of light and heavy combeen treated for the purpose by passingthem at poncnts; in the manufacture of greases and semihigh pressurebetween surfaces in close proximity; fluid lubricants, to make productswhich will not and at the usual velocities or rates of flow, the hardenunder low temperatures icy-adding com- 7 Wear on such surfaces has beenrapid and extenponents which do not so harden, usually the more sive.Hence poor results are secured in operafluid component is apt toseparate during storage tion, and frequent and very accurate refittingand under higher temperature; and the invenbecomes necessary. Where onlytwo adjacent tion can further be utilized similarly in the mansurfaceshave been utilized, conditions have alufacture of soaps, cosmetics,emulsions ofoils, 75 ways been very troublesome and where a larger suchas cod liver, castor and petroleum oils number of such surfaces wereincluded, accurmasked with fluids and pastes surrounding the ratefitting has been found almost impossible. microscopic globules of oilwith more or less fluid Hence the passages between said surfaces throughsubstance of less disagreeable odor, taste and which the liquid waspassed often became such appearance; and to improve the oils themselves80 that the liquid in passing through them met in regard to theirdigestibility and qualities of with too little resistaneetoaffordeffective operalubrication or assimilation, due to their homotion; andthe liquid when deliveredwas apt to geneousand more finely dividedcondition. show very-slight change in character, and little With theabove and other objects in View, the

or no approach whatever to the degree of homonature of my improvedmethod of homogenization 85 geneity and uniformity desired. I I maybereadily ascertained from the following de- It is therefore, theprimary object of my presscription considered in connection with thetypient invention to provide a new methcdof homog cal example of apractical form of apparatus enizing liquid or semi-liquid products bymeans whereby the said method may be performed and of which a morethorough and uniform disperillustrated in the accompanying drawing, andin 90 sion of the diffi-cultly emulsifiable ingredients of which- I theproduct is obtained, but alsothe objection- Figure 1 shows a device bywhich the result deableand excessive-wear upon the parts of the siredcan be obtained in the practice of my inhomogenizing apparatus requiringmore or less vention;

40 frequent and expensive repairs will be obviated. Fig. 2 is a detailview of two cooperating parts 9 ment of condensed and evaporatedmilk toprevent In the particular illustrated example of ap- The invention canbe utilized in the case of in section between which the ingredients ofthe milk to break up globules of butter fat and the liquids are forcedto flow under such conditions like into much smaller particles, and todivide that uniformity and homogeneity ensue; particles of cream to suchan extent that same Fig. 3 is a bottom plan view of a portion of onewill thereafter remainin suspension and not of the parts shown in Fig.2; collect on the surface of the milk. This result Fig. i is a sectionalView showing a modificacan be obtained with raw or fresh milk when tionof the construction of l ig. 2; separated for standardizing, by adding adefinite Fig; 5 is an end view of Fig. l; amount of butter to a definiteamount of skimmed Fig. 6 is a bottom plan view of a portion of 50 orseparated milk, which is later made homoone of the parts shown on Fig.4'; and

geneous, and can be sold as an improved product Fig. 7 is similar toFig. 2 showing another modifor infant, child and invalid feeding, beingmore fication. digestible because of, its greater uniformity. On thedrawing the same numerals identify the The invention can also beutilized in the treatsame parts throughout.

cesses 17.

paratus by means of which my invention is practiced, the numeral 1indicates a head having an inlet passage 2 and an outlet passage 3; thein let passage 2 leading to an enclosed space or chamber a whichdelivers to the outlet 3 and in which the liquid undergoes the necessarytreatmerit to impart to it the required physical character. The part 1has a threaded neck -5 through which the outlet 3 communicates with thecham oer 4 and this part is also provided with a central threaded bore 6terminating in a conical seat 7 below which is a smaller bore 8communicating with the inlet 2. Into the threaded bore 6 and. engagingthe conical seat 7 I screw a threaded bushing or sleeve 9 having a head10 and the outer-end or entrance to the threaded bore 6 may becounterbored, as indicated at 11 to receive the head 10. The head 10 hasa passage extending through it, as indicated at 12, to connect the space8 with the chamber 4, and this passage is square or has a shape which isother than circular.

The extremity of the bore or passage 12 at the head 10 is expanded toprovide a conical surface 13; and fitting into the'passage or bore 12 isa stem 14- having a conical head 15. The stem or shank 1 1 is preferablyround and the head 15 is conical like the head of a valve forming asurface 16 which matches and cooperates with the surface 13 in the endof the sleeve 9. Hence the liquid to be treated on entering the inlet 2and reaching the space 8, can-flow through the bore or passage 12between the stem 14 and inside surface of the sleeve 9, and then by wayof the annular channel between the surfaces 13 and 1 6 to the chamber 4and be discharged by way of the outlet 3. The valve-shaped bodycomprising the shank 14 and head 15 is held firmly in posi tion, andwhile passing between the surfaces 13 and 16the liquid is so affected asto receive the characteristics desired.

In most prior constructions the surfaces 13 and 16 have been made smoothand shaped to fit each other accurately, so that if nothing intervenedthe surfaces 13 and 16 could come into contact over-their entire extent.As the liquid to be treated wasforced between two such surfaces as 13and 16 at the necessary pressure and velocity, these surfaces quicklybecame eroded and pitted; giving riseto defective operation andrequiring frequent and very accurate refitting. In the practice of myinvention, however, I avoid such erosion and wear by altering one orboth of the surfaces 13 and 16 in such a way that, while the liquid isforced through at the same pressure and velocitythe wearing away of thesurfaces is pre vented; the ingredients of the liquid are thoroughly andintimately mixed and the effective life of the parts is vastlyincreased.

To achieve the objects of my invention, I proceed as shown fully inFigs. 2, 3, 4 and 5. Referring first to Figs. 2 and 3, I make theconical surface 13 smooth, as before, but the surface 16 is shown asbeing pitted by a numberof small re- -These recesses 17 are arranged inradially spaced circular rows on the conical surface 16, all concentricin the embodiment shown, but the recesses or indentations in each row,instead of being in line with one another radially, are so situated thatthe recesses or indentations of successive rows are staggered. Hencewhen the liquid is forced between the two surfaces 13 and 16, it doesnot take a straight radial path but has a tendency to follow the zig-Zagline of flow indicatcd by the dotted lines in Fig. 3. This tendency isdue to the fact that the liquid takes the shortest path between adjacentrecesses and as said recesses fill up they form minute pools. In itsflow the liquid is simply transferred from one of these pools to anotheruntil it is delivered into the chamber 4. The recesses or indentationsare of sli ht depth but they serve to prevent the liquid from issuing orSpurting too rapidly into the chamber 4 and thus the usual erosion andwear are eliminated. In its passage through the annular chamber betweenthe smooth surface 13 and indented surface 16, the heavy and light components of the liquid are attenuated, finely divided and thoroughlycommingled and when the liquid is delivered through the outlet 3, thecomponents are so fully disseminated through the body of the liquid thatit has the uniform and homogeneous character which is desired.

The mating surfaces forming the passage for the milk film are veryclosely related to each other and fitted together with extraordinarycare. While such accurately fitted mating surfaces would alone result ina certain degree of homogenization, I have found that much greater efciency with a finer subdivision and moreuniform dispersion of the milkfat is obtained with appreciably less wear upon said mating surfaces bycausing the milk film to traverse a multiplicity of spaced pools of milkof small area located in the path of flow of the milk film, as by theformation of the pool collecting recesses or indentations in one of saidmating surfaces. Thus, as the milk film is projected under velocitypressure between these surfaces, the fat globules which are flattened orattenuated between said surfaces upon entering said pools are brokenaway from the milkfilm and there surrounded by a cover of serum, the fatreturning to its globular form and being preventedfrom amalgamating withother fat globules, and thereby. retained in perma nent suspension oremulsion with the other constituents of the milk. As the fat globulesare successively transferred underpressure of the .milk

film and in the direction of flow thereof from one pool to anotherbetween the ingress and egress edges of said mating. surfaces, thisaction is repeated, the portions of butter fat being thusrepeatedlysubclivided and caused to assume smaller globular form. Inother words, this continued movement from pool to pool, subjects theglobules to repeated flattening or tension, and while under tension, theindividual globules are subdivided, such subdivision resulting from theshearing action which occurs as the fat globule leaves the pool betweenthe closely fitted metallic confining surfaces. This shearingdisintegrating action upon the fat globules occurring a great number oftimes in the passage of the film between the metallic confiningsurfaces, insures against the return of the milk fat to its originallarger globu- I lar form. It is also likely that some microscopic fatglobules imbed themselves in the crystalline crevices of the metallicsurfaces and grind down other fat globules by a process of attrition,during which some electrical potential may arise, thus aiding in theformation of smaller globules and preventing these smaller globules fromcoalescing into globules of larger diameter. The action above referredto is facilitated by the conical form V reliance directly upon highvelocity pressure in its than theheads 1G and 15.

order to obtain proper homogenization as in the methods of the prior artheretofore employed. In the operation of my new method, the pressureneed only be sufficient to cause the continuous flow of the milk filmbetween the mating metallic surfaces and its discharge from the outeredges of these surfaces. Any increase in pressure merely results in anincrease in capacity output, and is without effect upon the efficiencyof the homogenizing action.

In the construction shown in Figs. 4, 5 and 6, the cooperating surfaces13 and 16 are both smooth but in between these two surfaces I place aperforated conical member 18 having apertures 19. These apertures 19 actin the same way as the recesses or indentations 17, causing the liquidto flow diagonally between the surfaces 13 and 16 because the apertures19 are staggered in the same way as the recesses 1'7. This part 18 maybemade of some material which is softer The wear may be more rapid on thepart 18 than on the surfaces and 16, but all that is needed to insurecontinuous, eiiicient operation is to replace the part 18 at frequentintervals. Frequent refitting or grinding or polishing of the surfaces13 and 16 becomes unnecessary.

In Fig. 7 I show two members 18 having apertures 18, one in contact witheach of the surfaces '13 and 16, separated by an imperforate conicalmember 20. This part 20 may be as hard as the parts carrying thesurfaces 13 and 16, and the two perforated members 18 may be as soft asbefore. In some cases the intervening member 20 may be perforated,grooved or corrugated but in any event such spaced portions aredisconnected or discontinuous; and the apertures 19 in the two members18 are staggered as before so that the liquid takes a zig-zag path fromthe passage 12 to the chamber 4. a

In each of the illustrated constructions, it will be seen that theliquid flows under pressure in a single direction through thehomogenizing zone, and While maintaining the film formation of theliquid, at spaced points in said zone the con stituent elements of theliquid are subjected to a repeated shearing, disintegrating action asthe film flows over the surfaces of the liquid pools which collect inthe indentations, recesses or openings provided in one of the matingsurfaces of the homogenizer. It is found that this maintenance of theinitial film formation of the liquid throughout its passage through thehomogenizing zone, instead of repeatedly breaking up and re-forming thefilm or diverting its course of flow in several directions, enables amuch lower initial pressure to be used than has hereto-' fore beencustomary, without lessening the efiiciency in the homogenizingaction.

The head 15 is centrally recessed as shown at 21 and this recess mayhave a concave bottom 22 to receive the rounded end 23 of a plunger 24,which urges the head 15 toward the head 10 so as to make the surfaces 13and 16 keep close to each other as shown. in Figs. 2 and 3, and to havethe same effect in the structure shown in Figs. 4, 5, 6 and 7. Thethreaded part 5 of the neck screws into a hollow head 25 which has aninternally-threaded rim and contains the chamber 4. this head 25 is ayoke 26,'comprising arms which are united by a threaded bearing 27inwhich is screwed a threaded sleeve 28 bearing a head 29, sothat it caneasily be turned. The inside of this sleeve has a smooth bore to receivethe stem 30 Made rigid and preferably integral with" attached to theplunger 24. The top of the head 25 is shown closed at 31, and ithas acentral boss 32 with internal threads to engage a packing gland 34. Thisgland 34 compresses packing 35 against a conical shoulder 36 on theinside of the boss 32; which of course is bored all the way through toenable the plunger 24 to project through the top 31 and the head 25 andinto the chamber 4 to engage head 15.

The plunger 24 is united to the stem 30 by a conical shoulder 37, andcarries a disc-shaped abutment 38, which abuts against the shoulder 37.This abutment 38 has a central boss 39, which is encircled by one end ofa spring 40. The other end, of the spring engages a similar '90 abutmenton the stem 30, and between this abutment and the bearing'2'7, are discs41 and 42, each of whichis recessed at 43 so as to receive anantifrictional element 44, thus a ball bearing is provided-which isbetween the upper abutment 33 of the spring and a washer 45, which mayabut against the inner end of the threaded sleeve 28. This sleeve 28 maybe turned to compress the spring 40 to the required degree, and the ballbearing reduces the friction of the parts when the adjustment is made. I

The threaded neck 5 and the inside of the head 25, may be providedWithmatching conical surfaces to receive a packing gland 46, so as tomake the chamber 4 leakproof. Further, the space 8 may open through thebottom of the head 1 and which may be threaded as at 4'? to receive athreaded closing plug 48.

In the complete device shown in Fig. 1, the constructionillustrated inFigs. 2 and 3 may be employed; or that shown in Figs. 4 and 5, or thedevice shown in Fig. 6. In Fig. 2 the spring makes the surface 13 andthe indented surface 16 engage each other; but the parts 9 and 10 canstill be moved to a sufficient extent when the liq- 115 uid is forced inthrough the inlet 2 to enable the liquid to find its way into thechamber 4, and the same action takes place with the other constructions.

In operation suppose milk containing cream or globules of butter fat isthe liquid to be treated. This liquid is forced through the inlet 2 andit makes its way into the chamber 4. If the con- 'struction utilized inFigs. 2 and 3 be employed, the

milk takes a zig-zag path between the heads 10 and 15 of the chamber 4and the particles of cream are so finely divided and evenly distributedthat when the liquid is discharged at the outlet 3, it has all thehomogeneity required. The annular channel between the surfaces 13 and 16is not obstructed but the indentations 17 or pits keep the velocity frombecoming too great and wearing away the two surfaces 13 and 16. Theconstruction shown in Figs. 4, 5 and 6 are preferred forms of myinvention because when the relatively soft member or members 18 becomeworn they can cheaply be replaced and the heads 10 and 15 with theirsurfaces 13 and 16, do not need any refitting. With these devices thelatter parts can be operated with-great efiiciency over long periods.

While the apparatus is especially adaptedfor the treatment of milk, I ofcourse can use it just as well for the treatment of other substances,for eX- for use as a medicine taken in combination with something elseto modify either the tasteor the action of the oil, the particles of oilcan be so finely divided that each will be covered. with a coating of adifferent liquid, soas toafford the desired effect. The liquid to betreated need not belong to the class of substances which are to be takeninto the human system as either food or medicine; but it can also beemployed for the mixing-of paints, lubricating oils containingingredients of various density and viscosity, and similarly treating anyother substances. The efficiency of my invention is f due not, only tothe fact that the path'of the liquid is inade longer from bore 12 to thechamber 4, but also to the fact that the recesses 17 of Fig. 2 and thecorresponding recesses or indentations 19, or pits, Figs. 3, 4, 5 and 6permit the formation of small pools, each separated from the other indisconnected or discontinuous fashion. Such separated pits serve tobreak up and to hold the fat particles in separated broken form insteadof gathering or collecting the same and thereby'acting as accumulationsof the fat particles as is the case in certain prior art devices whichemploy continuous grooves or grooves connected with the pools. 'Themethod forming the basis of this application consists in flattening .outthe fat particles between the flat parallel surfaces, and thenseparating the flattened particles into smaller portions and holdingthem so separated without being able to again join together, and thenagain flattening the separated particles, and in turn subdividing these,without allowing them to join or accumulate, and the liquid flows fromoneof these pools to another in continuously changing direction on itsway to the chamber 4. Thus the fiow oi liquid is not retarded; itsvelocity can be maintained at the required point; but the liquid isprevented from flowing with too great acceleration into the chamber 4;as it woulddo if the matching surfaces 13 and 16, were preferably smoothand with no such members as are indicated on the drawing at 18 and 20between them.

The subject matter of this application is disclosed in my pendingapplication Serial No. 291,018, July 7, 1928, and of which'the presentapplication is a division. 7 I havev shown the preferred mode ofoperation of. my improved method, but change may be made therein withoutdeparting from the spirit of the invention as herein describedandhereinafter claimed.

I claim: The method of homogenizing liquids, which consists insubjecting a fat containing fluid while under movement, from its inflowto its outflow,

to a yielding pressure to flatten the fat globules of the fluid, saidfluid flow having a substantially uniform depth and simultaneously atintervals enlarging fluid flow to a greater depth than vtions, and such.portions, as'they'rnove toward the outflow, are separated by subdividingthem into further disconnected and discontinuous portions, none of saidsubdivided portions joining with each other, duringthe movement of thefluid from its inflow to its outflow.

WILLIAM H. BROOKS.

